RE: [PoC] pg_upgrade: allow to upgrade publisher node

Dear Hou,

> The BF animal fairywren[1] failed when testing
> 003_upgrade_logical_replication_slots.pl.

Good catch!

> 
> The reason could be the length of this path(262) exceed the windows path
> limit(260 IIRC). If so, I recall we fixed similar things before (e213de8e7) by
> reducing the path somehow.

Yeah, Bharath has already reported, I agreed that the reason was [1]. 

```
In the Windows API (with some exceptions discussed in the following paragraphs),
the maximum length for a path is MAX_PATH, which is defined as 260 characters.
```

> In this case, I think one approach is to reduce the file and testname to
> xxx_logical_slots instead of xxx_logical_replication_slots. But we will analyze
> more
> and share fix soon.
>

Here is a patch for fixing to 003_logical_slots. Also, I got a comment off list so that it was included.

```
-# Setup a pg_upgrade command. This will be used anywhere.
+# Setup a common pg_upgrade command to be used by all the test cases
```

[1]: https://learn.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation?tabs=registry

Best Regards,
Hayato Kuroda
FUJITSU LIMITED